For example, there has been known a directionality control system, disclosed in PTL 1, which forms directionality in a directing direction toward a sound collecting position of a sound from a microphone array device. The directionality control system of PTL 1 suppresses the output of sound data of the sound collected by the microphone array device in a case where a designated sound collecting position of the sound is within a range of a fixed privacy protection region (that is, a fixed area for protecting a person's privacy). Hereinafter, the privacy protection region will be briefly simply to as a “privacy area”.
However, for example, in order to monitor a situation, in a case where a place, which is designated as a position where a sound is desired to be emphasized by forming directionality (hereinafter, referred to as a “target”), is a privacy area, the output of a sound is suppressed, or sound collecting is stopped. For example, when a point close to the privacy area is designated as a target, a sound within the privacy area is heard so as to leak into the sound of the target, which results in insufficiency of privacy protection of a person within the privacy area such as contents of a conversation being known by another person.
An object of this disclosure is to suppress a deterioration of the protection of a person's privacy without making another person know contents of a sound uttered by the person within a privacy area even when the sound is uttered by the person.